SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b7c9581e69f3c95bbd8feb6355658dac63ab0bee91127d8878a4f595c91e315' 
  AND token = 'viotxBhYGHnP+tiDJWk8PcGbu1h/LkYhphd+YFJ00L0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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