SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47c1835894abe210d9f887ec1bc080252d7e6d1a5c8c580a926f307be22a2af3' 
  AND token = 'pOxgOvqGzalQJhdCpPOZm/4nuw61gjxuaayVJhdJfes=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00165

JSON explain

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