SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ccb37d5ffecf666e5388b1a868e9e056499aec678e96d75fadf8964211cc99f' 
  AND token = 'WSY6/b6rxpzRpPWZoAD/SUquFztT2H8ZyGVWbheF6Ho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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