SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '837a858df0cecb44a27ddeb93594c6b0617a6d19436c1cac890830b488df1c29' 
  AND token = '/2ZIWrZjKYrSbsFTwiW1M8JDh6A4lN1mZFl2YkHNu6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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