SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e13e67893a44d89af0889376475e0a8ce859e59ba6713f052d51c0d7b2d2274f' 
  AND token = 'FMSdF1R0GugHajCG5ONVWYF0I7o91+hcM+rbdcF5Z3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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