SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '327979d552a491e913beda9f7da005455c77dab3d84890d77ebc88e2db9b5d3e' 
  AND token = 'UZhsNYsP6DndX9XTGAHtpatcXBaS1BDKZbetNWv4xE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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