SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac990eb0e17764fd7ce27e78993b4b20d259cce5d53d40e78d6bcb8c8c09a8f7' 
  AND token = 'YfBzOGk4yb0u9M9xPmRsKSgg9X3DA26CtUl3xNGFPU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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