SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3061b5318f74f45ac6d9e00805314616f79212e6d38587620cd361406a34987c' 
  AND token = 'jRsZFUmInVTxgIaX+AmXQrM7kqQe/LmA+bwv58RUMDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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