SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88c7370a2e2b1f8452e9b6e518f46761d2e53bd590c29bffc53d846b7aa58c96' 
  AND token = 'V97fgpywju+ykLhl+DNs2X402G9qyCzo/ex2iWJhjv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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