SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e04bddd1fa3e770520c5de49a841446f2bb9610eb201b4e34962d81f35d9644a' 
  AND token = 'Z7x1V1JpopV4no0TiyMij+SURHVnrFFgjPpn8JbRNJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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