SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11a30efb46bbde007ed4938afed5b0f340db6986603d45a172ca63e6f34d0264' 
  AND token = 'HSVBzGfNEzRTcLXXsqerA9pUOWFqOpwrMDtwN+yjdJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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