SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbdea2373f7e958cab5b3929b39dbf6be246287a337759a63699ca8703c894a6' 
  AND token = '10uor09n9+ayGXD/gPUwR38Big0exjT0jG2mV2QhixM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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