SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a552b1b075262cc0ec1c34245597aa14289852e970e8d299e98692fa0dee24a2' 
  AND token = 'HCLn3pPdfbeJcCiLc7YOzyTCXmj0KZTejt77cHV5Nys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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