SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd0751e53594c847c8f5ff087a823da81e58c1d3623b5cb3266ea6b806a3cee22' 
  AND token = 'C6eDSA+bCu2S3BJYtjN+tg/dTGIbuYJmv89pthCwa8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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