SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c539150cec9b25a388e3172350ee99f28320a6690188a70537b4e4753e873bbd' 
  AND token = 'hWe2OWsyCZTavLvlam8A0UqUDenax5UUX/FFjzStzKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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