SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ce4b85682449147245ad4b8099a59e03df0f811da1cbf7435c38ff6816079f6' 
  AND token = 'M9hCbZK+D3m6fzMiz1DITfGL2BfZEiM/7qGo2WBjGyk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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