SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b6529010a57057aedcca2c12812fc36fdfc21215a42a15bae38c1b7ccc6015a' 
  AND token = '5raP95cAjeSo5Pf/a/utk2C6yqVZi0WpQv98yZAugzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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