SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0c93eedd4257f44e93a25578a8cbd24fd06fa42a6b8b317a1f9c217fbb7b46a' 
  AND token = 'T7gz0w4JViCU18jiKz5uImp2ualv2ZEYYdjGxmUjmSI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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