SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '21d31123e0c93dceba2b78db93f0c28a0509a41f3924717ec52103bdc122782d' 
  AND token = 'hUFVGGlF6qES/l0NK8OfHVkgpBP1dOKm3f6cNymjYiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00767

JSON explain

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