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SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '577ef17bdfad746b04b7ddd040a9ff6bb9bdddd128cc6660a58d0e7785fbfac9' 
  AND token = 'Bd5mNEWFoIeDU8iel9/awiY6MasXYNnt3qfm3+AbYVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00986

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}