SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24cc1dfdb987988e2126797b54e198a5ca159c1d1a537d407ebf08f98048ffa5' 
  AND token = 'cbt9hCHZEFlOmuCq9VPmUu+fP2tYH8gNzIDYs3GxjmI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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