SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '4471987345931138d5a0c5b844ae7733cfd12206cf76ac09a6a91641b7e48df0' 
  AND token = 'w+tZv+MaloN236ph/mTO0Wj9wqRTuTxv2hhF+IJPkos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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