SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1034edaba1a6cf45c219c3a593469e021a29556b117cf208e92b136e3c070bc3' 
  AND token = 'Y38cWRv3+SRafxeOui8dP7Q8cLNmfz267xKpmLYuIYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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