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SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '871f8bbfd1b25426f2ff968fd4825f3263c1e514dfd0b7aea7201b2d5e52fd6d' 
  AND token = 'UEwk3zBfP5sVC8rw4T6LVg/Fzbdg1y876wdaMNqxu4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00846

JSON explain

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