SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '42c933b6344cc32a8ca35f63b737989fa8918b6096239d1900ac09f1dbfd43e3' 
  AND token = 'IA4rhuH6jks1lIy7pVrJqhKvZoT/mtP2JpBbRwwspAQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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