SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45f0ab985825846e885c7048c83da3aaa0238730d7e4f004b2896141b1ce0ddf' 
  AND token = 'RUpbxuIBUuQWnTJLUQg2r5n9LUPFm1CZACOmrs3H+B4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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