SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '176d9ff83e727fb60b3ce70def1730740718fa129fc60952dea3dcb73e6025ec' 
  AND token = '4oh52H/METHCMkwhQpVt39RoprdHgX/maVP+kPeU+WE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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