SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31abdbd99fc8157d3b8295f4394f22699d492d7e6847b56574a159046daa7b20' 
  AND token = 'wtDakgTrw/5YlQQjvTsU1sPR65vAwVX1FBADiLpc8Fo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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