SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d39654f27b53b4a23d6e703718523f4939fe954f690011bf48dddd8533a8430' 
  AND token = 'XWjnIyM4hcOKaovlTHhRV5sGMqqllXfye4jw/3hfYY8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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