SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c676abb69c8f1ab019c8ef9682bfefa95145fd41addfc9ff8d54dc41e286a101' 
  AND token = 'V8tUN+upJqMrrjaOpe8uTACue5S4KrFcmQV8Zf08KlI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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