SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4a2f815dffcb3cbed1e752f9d30ecc16c41db804497d7599a910dbe03d43e2a4' 
  AND token = 'cf1xpxw6pJLIoV0jmUy50ziyUHpyV3RDOkZGrFOslbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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