SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0eb958ab65f641c61ee0a4c163f944458509483b7092081e32674e72ff021a61' 
  AND token = 'BB/Rkth9u9Cm69U4gIEDtdw8iD8jwZyFn1sLaEH/jNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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