SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '507c0f9a5881b397080f589e4fc42447675cd57fa9ab6a0ea397445c16fff4af' 
  AND token = 'eRnZdlUvmg5lwjT0L/ZF5mB5Yqbc5PyfzDY9FB+jMlQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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