SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6dec69687383674d8efac57dfcab2b330e112ce7194d8b5761029bc0cfef8a95' 
  AND token = 'dvZZnEiFrJ6iDnR/uoaEt3TNV0WMnuNtPQFiknbpBPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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