SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '102f734aba2535249eec0ce1d0dc5a16a93785aaab7d7056598de923593b9ada' 
  AND token = 'D9zyOmT7eW/Mi4ZmntQTB3fOvLFSCisZg7xDBDeN3sE=' 
  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"
    }
  }
}