SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '559534b461df7539cbd35836fc698491728c4f66f9cf17548f5cce5838630ca9' 
  AND token = 'hRTTLBIq6B/0FJzzDdH+YJLrhn5muoiPA8X4LR+UQZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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