SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a7ee26f2fdd55459bf9f4ede9079628cebda61c76aa115110456f713b6e8f04' 
  AND token = 'EIjKUB4/VB1B+TqO6k9DJY4qaOX6j4N1V58ZBGX3p3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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