SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba2b6a31f3e7d37dd64623bfc66eb8f575cd1c24eb8cea2b69fb4f06190a430f' 
  AND token = 'l3dHuscUDtGYNHjZlRnhEh5oR84K6KBKCHd//Bbewuw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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