SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8949bc04326a18492753b798960f679623caf81be671d28d16f8b649095a7f7' 
  AND token = 'ZiXrSjroEwuW2HsEjRMffaXM8Ujl1RST/aRjXjWb0cc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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