SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86482798f22a3805a04ba54f09768a07bd0cfa3fba4f4d68623d1b4a125509c3' 
  AND token = '/QVM1y2PqNqY5ichsltSDGnNIw3l6+grHSQbF+mfmV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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