SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56107f8094bfe9ca488b58458d9a6a919b50cab0b835da103877f07095855212' 
  AND token = 'ytsulXQW6vVifVKGvhbBVuiMYJoethv+/kMlFkydOag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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