SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3230dd5a80f64fc98c78b01455bb9ccff8ed431084ceec61f3084fb68c1b2f00' 
  AND token = 'kbOm4HBb6+Om5dFh+7gEJC18hM07F5YqCXPPRYzMCMk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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