SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'db45eb67b2bfdf191c4c508ec5c17b97b97fbf144028c47f24d40a1e96201a19' 
  AND token = 'DkO2hKD5Xk9iktUseq1cPfQpDkZwAPX9tC3ij+W4GdM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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