SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48562c8cd5c5bd1115bdc5fea551b4d8e301f30b544fc2d44647faac6ccd93cf' 
  AND token = 'D4MqOeJpakRkXyjc7hp5prd8hnaQfUqY317t5CdD4gE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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