SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2cb60da3b9908eff3794ca40f7971babc3b158b3519ac7cce6f9e674be89dc64' 
  AND token = '3vr7ITlwvuxiOcbnSfRRxY7RpMni5TMkDhgL8H2loho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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