SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67f54e756cb2c88ee1907103e14b632fbf0866402f56e8ee564e2ac15858b8cc' 
  AND token = 'LurVF/2QhT6UKaIqhmj4HwLjTQTUh7+qrZ9iuleMG+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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