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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '99e0ad1161d54087f15ee0bf4cf1a1939b9b06494b44539698d103d5bddc5e7e' 
  AND token = 'd/R/c2QNqs2Fa8+yHOCI7X0xB4xAXQQ8rZFL/NYGx7M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}