SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cda93da9764b31561e87daacfbaaf70cc2423f93faf59c27f72b1ad7cf3fed1' 
  AND token = '0BoB0lRsR918Vr1qLzw22OintyeomGMUa/5Xtkpri5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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