SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eeb80ba85888e02e01a2a7cb35e5bbfa45ff2f1ea911bc4cb781f8486de5f6a6' 
  AND token = '8CtJKSVq6gSkCOWbQiwf3OSFd1nxUj4UZo57GojYRSk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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