SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ee967b901c86990263ebb7775f153a6d50d7915faf8152312c7d4423c6ecc57' 
  AND token = 'DR/X3hT5U8zsvstI71vOyKHN8ZRj2zisIuK4R3BhJmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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