SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '622331eca5212651473e70784873d7a3e9f45eeec58eafffc8caa7c4ac1cf191' 
  AND token = '35cxzrYuYekKddOK/3niAW+Jb45Ar8QacUuoqjU9N6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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