SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc71e5898d0b7418cc26fde89ced5f31f7a349bef9ecb561ade53704a9c520cc' 
  AND token = 'bqWLf9xajgugwSVzfP+655zWuFa2HBSPvJ/UMUMT4vQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}