SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef498b9f2f67d85c2dc89491384f7c88645d2157d9737de900a0277da9697e1a' 
  AND token = 'mY1AwzhSIZgG1eLaQbX/MPrAbg+6r7u8439RDUzJomg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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