SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a1a67b42bdd6ec4a75edcff9f7dc783af8fe8b3fab87b434c48159851aacadb' 
  AND token = 'Cid+IyBeuAbU9HKKtWpIvZFnUxA6Y5UqZ1Tru2napyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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