SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56e591bf36bfe10112e43234c9649c2da838cd48000e4275ec6ba685d531c5e4' 
  AND token = 'bQtKSQgjWM1tmGMIhBblXyHO1QetKoSHFyuamW3V9BY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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