SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3440e3f396e683ec3cb3b45e78e85d262ab778af6ce21c188ba4246e1610fc9c' 
  AND token = 'zKqMstv8O2WAnOchhOyOvBWo3iYuHQPaGRXhaMCDbjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}