SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26ddf3e6e77360b1e1931af18689a5e582b4ab325dce83a6fa7aa02cc0b6599d' 
  AND token = 'sRKOpG/v1KuhcV7qLBhVjAWqN8rM9+oitYqeE1TAOQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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