SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecdc34f44820bb0407e8e825fbbb0d73991d945eabe85cec85cae459e7dcc491' 
  AND token = 'I+VifNTICsgZiyd96WlHnmifpPWmRrVC0cS9GPmQbZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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