SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4593ae87ba74806edba1d93d58266e094c83b5ecbfdd5dad92ad61c2f160541b' 
  AND token = 'vJ4ZQmbLAo5lAaSG3o37F5pZi8GIqAF4NXMj8rAqlhA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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