SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '117d2515bdafd20c0021d84e00aad5b1cf2dc2e1baa312238f2b8a4e3ca8f42c' 
  AND token = 'pZiXv16sB3B/LCwYicjDpCHIHjcmUxGmGdiN1mKLHVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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