SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9d318b6a6bfb5dee4f4f423831385ee48825d5e5d2a5100d3d95abe229e8b34' 
  AND token = 'FJPpaLfk08qA4+C2gqUuu5iG+Ta4zwx1TD3FMraEmaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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