SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d93956056405f1b015b856b6527fbb2358f434e80619baa9fa624add01c0bc0' 
  AND token = 'Rs7ZoxcwtK3eWM2yoh89quSgwKJhHBgBrnaLpli2AKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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