SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ca5485ad847f64a3ba8e97bf3485f04ce886d6109ba709ac9f91b9049818243' 
  AND token = '9HmZqFdRUe/4dO/5SqYBUn3PBJ5BRKprhVDde+CKD9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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