SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68eec826723b838c826de986d31a2cfab65ca61339a13b558d8abaf1e3252994' 
  AND token = 'm673xhaT+b1lGzJCveAU8jdRSfKhDTZMFPoaY8NbYRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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