SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbdde5d106082033ce0209ad61fc6cbfcf68ec451477eea136e8322011ae2a47' 
  AND token = 'LDiT2pah46jHu6He9LotHHTaoA0rzVpTwymIXANG6k4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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