SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91c09ccb12d4e8867474c6375df021faf953bc33ca25c44c8a539020679f7e2e' 
  AND token = '0irXP5ys1qKLEKoK1YtodMO0NYVl6AqEf0dj6YQj2Hk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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