SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b2cd6ea83527be66eed45670542de27d45f24efb83e1c9d82b3efe2eca00bf9' 
  AND token = 'ufvIQDPUur/h7zhEkbd4pe57p7MUD3pnTUg09XNKpY8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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