SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fdd60117ca34bb44ba26d4cd778a6f6b8b9b982bf71228b85c2fb44b11bed5d' 
  AND token = 'AuTYXvR4moL49cfV5qcSKyJIHwX7K49gjSFYm+8a5lU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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