SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd08628155dc5e22f91e5236df2c03ec1c022080cb3850f493a0cbbc29e07522' 
  AND token = 'zvyGznEHpIQ06mtQQqWfTG29Ao+gB3r9Bq9RjaKSjYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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