SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8bc05bd53e1b7337332b640521ad768159109182f790a0f40701103e20e1810' 
  AND token = 'axSVFFAj/fN3DzObgTt996x5x5AK/u7u6gr864n+DVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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