Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd29cb35165e5af936bab4da393a702291beced01679441699a50873d671ef0d3' 
  AND token = 'PbilJbHdLzaNOzPgog2yhM+FK7/qM56KTDpy/eBox00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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