Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd81681e428106c4cdcdca8e3424c43e85577caec5f051da770c1068a6eaa5f1e' 
  AND token = '7k0bU7ehZ8IbCo2ee2R4s2SvCB82UG5jDuocD5Q4Fv8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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