SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11e76a24705e07678b81c890514c8501f6d18e4dc080aeedd5091fd288030a6c' 
  AND token = 'siU44FgkMD7tJfhyisEU0Gc4tCkcQtuDtTUyS9Izp/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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