SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd615e9c125fb59aaeff05a92d05a47480d73efa0091bb4e574477479cc946bcd' 
  AND token = '3nLbHWcUak81d4qjVzfjZoZZBa3umC5tUsGDpZWGtME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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