SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f0dc9c7ea9f10fb735a930bc560c85f968bde17123b013d63f03b1b1cca48fe' 
  AND token = '7E6OAML69YwqO/Gh/GxS+RqJjyBsVVFZFVn5CH06iGE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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