SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0db6f42e03cc1fd237174a825cf5ba76b7da6b833232e0a00c2ef93c751380f' 
  AND token = 'WPYllAjbdVCRPqYx569lN+fUtwkGaWvZlXnNorO0iHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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