SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a393a67a04c1b39086679a6ec9f8351deac87d12fcbc0f28a49cc974d4c7ddde' 
  AND token = 'hMWHNpNlMgtadLzKH6BpXvzFiafxROtDitm/mi1T4lI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}