SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96d2ce725cd12907794cc3954d0d876e42a0f000bd2fbf7de02bce3c876d3444' 
  AND token = 'EYQaDRc2J45GIOOrBPGlxLnd/7oAQoNQmEIvvxo7wkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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