SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dc3d553cf65640b1b99ee13cc02c314526219cdb22b2ecfd8ea5b97a7e84a47' 
  AND token = 'fdXrLjXQIJ8JwN1jjb/fyzq3QyKONn4sOyy3WntV7EM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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