SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c866ea6ca5a2bf3a197c5b0a8302058031294a127ed7d24165f6c9c183e333d5' 
  AND token = 'TTUEgrtEG2b1jcBHXfWKePLIemHYvIVGIIIoloFgbMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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