SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '102c90e6f94535890ea330c97f50d08bd7d6e5cec7226029313a24d31b7baf20' 
  AND token = 'fAi5NlGUQ0HWaNpXcSgFT/u1930hWwjdXYMOFxDIccc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}