SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '081e9f078ac213ffa67f63268dac17dce4cf81665b027c66aa263405986be115' 
  AND token = 'nQ1AY1VgXo+pXmxZEMm+58U/0hwyiUtufcQTGfZxOK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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