SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24f68551b9c12b3673a881e7449fd9197974779069e3adf0aeea6c79f06dc903' 
  AND token = 'X3fZbmGF7QqUIwYjKLTVzjKoaqx25g1hydZ8S0E6zlk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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