SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'dd783d1dee1f0025045c30c6ed1382ca54a4e424b57933560b035fd446cc1130' 
  AND token = 'h4AS8OVecm7tc8ORBlxG1rcXhpeKW381V9keTuWXSqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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