Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ddbb44eb36b8f5efaea75d64964057d0aba5a402ea7f4360a9e26701956b7a95' 
  AND token = 'WbcktGOdl1yXQ2Pej+Lm17jtCd4poWcExWkCNHL//zs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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