SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa17b8b7629d8f89e32db752687bf1f0025cab283dbd8458e34fe2914359385b' 
  AND token = 'z6y+UOg5Sp1gY//gay+jUGfu7WaAAuo69IwJU4ZMenY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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