SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f41fe8880975274275b1f07126fb2c7b52d6ade3a615f3daebf94aeaa35f026f' 
  AND token = 'u5sMzo25s11ZclZoLhJcMg5MFzklr6tFOlbW5cZIw28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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