SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '008da4382c494786bb2d3b19ba5e05e6c27e8110685c7371a52fb44ccb6f7a3f' 
  AND token = 'uzrz37ty/JXuDwi23bfTcJzuqChkigwje5mg4G7F+gM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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