Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '6e16d957ed3740e55a115799f18cc87b7bdc68c3ae673fee947517fe9b78a1ff' 
  AND token = 'eHFDVBu0jAwjJXlRn5uZLztuxUjN+TuD8UeYV0Jl0U4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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