SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f67230ee5f56fdc6cd57f8695f51729e706447c758bdbb4d24bc3d9ff0cf470' 
  AND token = 'iwDIX56zWqoZ0pF4nGrMj/BS6+AfzYcC02p3maVa6ME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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