SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc434c97a63030e638d98f711b9a7ecb75ad455b678eab010976ec111928191a' 
  AND token = 'Qys032Ygx1OwPLWao6TqsClijQlK7RyM+fSaeS16HbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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