Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '240cf61fd01c52aa88be8d529b766f1fb280cc79e08d75dc65fd6605a6e44f9d' 
  AND token = 'SR2n3ncnZ66bQ5cc6WGBq4CwUsfjMwr0fbDLA9+L+/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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