SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f65632c4e4f120f1b3816fd44d8a47c7ce6547f10e0b7baf8655aee2e96f75a1' 
  AND token = '5JjXdX4iu+2ZXnpQKy0M+KoxjLN0KXz+vKFwDZ8bqHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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