SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23c7f8018351f1c4bedd2c6786743dbc02aedf88ced0ab1c15beced2454d635e' 
  AND token = '+nlVwGXWRIPMQ6RyeK8feAUdsaP9V690Gnnirdot8tM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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