SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29d5cd4fd2db939a07109e49fdea843da4fa54e1af82c95db9ca908a5714f675' 
  AND token = 'mvy4TVquyUFEGMnK3PWjGY8cZB/bIFShOllGWzMfTT0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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