SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e65fa9ed881c67d414946010702b115930d9cbf371591c9a1cd4d58fa65096e7' 
  AND token = 'g+RHu9H7wrhfPbFzXkwJTsL7agPgKrD2/QUz8NlKhOM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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