SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a49509b97c6b66cc23a6c29574d41fba3f87e1d535d16a6d9c20956cc9686ddf' 
  AND token = 'BVcrGliTuqpfIBVEZhDCBV6KcaVfcrY58LkU4LhWwxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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