SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b58474e9daefe17400cee128935bfbf43da0a59e570662661f9fcb483a57ca3' 
  AND token = 'x6GumYiztT7sGJfF8w067SNWF8jO36vnj1j+KHMJ+CI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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