SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b156dca8f5d4563a59836dc2654751fab6dbc7364482124947616102326c8ad0' 
  AND token = 's1RK03Evur2lhL0/jwTwqUqaVoA4Xl7okOfWgwpIeZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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