SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30ab1264542229029e508206e646a07d4b72582d98e4a69716ffc7622aa0055d' 
  AND token = 'ZPuJbhz9ltJky7vZ1lgM1wvOQWrFwZxRzGGJC9q5qmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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