SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '474ff7da8f319d11905880413b0d7e2da39da07769893b503d0ebbac0c74ce58' 
  AND token = 'qEBPo180KG3Ra34kujEgvpPBoMy2DpvAqwu7Ucbb/7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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