SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f5c814a8c29825d62721699da538eecaa0dff28a1e250f1d5ca39f3a41bfeb79' 
  AND token = 'Ck7R70VDZ6VmEHmqU1tkLqbw0UAjpNj01JJiwaFqEDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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