SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c8d509e26dedcefbea1a15157a0e4f9e87379e9bbf0ff65da929df48c5a481b' 
  AND token = '8wWu3Auj2H339uLNFsgcEEFGb0bfDlH1gmkaWNGHk1I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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