SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3636623971bff114a6704685e20e131bf2a563eef71f10fcbbb2449ae44c27b' 
  AND token = 'ARhGXx9qT8jVjgVok4Kr+nrpowOrUrjDcIrHvDN9Zcg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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