SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '586d12703734e24741121b4072567053b51f875adf871d08ee65d3bafe5fb9c0' 
  AND token = 'W04DKPLf3J5aHjHDKYnJFl/MskZagm6yMwXpPHu46l4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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