SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ec7daf0be58e391e216abcf71f0bd298fb3650f5b58d92335322b96855bcc36' 
  AND token = 'YlK5mfwsI7SZB92jJMWBnTZPspu4CAUrsJR+oYjqC0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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