SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '7bcead4947b8d2c22672193d577671d1fd0e21ba90bf35b48875a35cda418b5f' 
  AND token = 'ErCg62ztyFdZqkHGFEA4/BJLGOk/VTRxlHyrTg3dMUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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