SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '55ae17153ad58b5deb611a9a12751d4c0125f0dcb48edd5594ea7ae18f96d666' 
  AND token = 'G+VzrPwhBfrDMR7eQWZcu4DS1XkvkXJNggU3EWwkwx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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