SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a0dd2ee113b13bcb2cc1b9bfb7a5b3d5ae8b5c9ecddc657ba2b6d7ed517473eb' 
  AND token = 'pqmfDM3jkfWEhcQagPpDDXbDBTPhHsun78NDWwmFGRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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