SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2f0fc84d7eafd61e3d092fbf40f6b5a740faae947dd48324412bf8deacd1709' 
  AND token = 'Ysbhh4O0vr05ErUJqTXxv63PKj1chOqtZ2wJJ58VYIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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