SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '35e5568970582fdd0b4ba70f5a948f5f81986fc1a153d59eea024c0190feb161' 
  AND token = 'h61jXi4WGSjBusBS0xBhxWRGDOKaY53mKSfmDJz2Ypw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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