SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6efc405bf885e345177244279cd900ffafa01bf7aa5040246d29a39d584c99f1' 
  AND token = 'Rz2D3D2wtGJHjufGHueCnzVu/0FINqtubQOrONH6Md0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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