SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfe1943a1d569ddf503430776fbfa7be81b6a509a97ce3ea6d32a1fe888cf819' 
  AND token = 'TmrEo+EBnr3aC76rlca/AYveJKkF4jpDLbTUISa6k+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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