SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d0d53d5c5c1b0b9249a1e900ab7ef01e60388802fd5229693152e7979534e5b' 
  AND token = 'QAS+0yCjY5aCC8rc0Koa0yjZ1fJwICMMpKkIa8n/Z04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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